Thanks, thats alright!
The clips were taken from a HD webcam that I have in 1280x720 resolution. They're basically just normal widescreen videos of me that I use for youtube, but was trying to get them on a disc for a friend.
I used Windows Live Movie Maker originally when making them (Its easy to upload to youtube), I actually saved them as WMV files ages ago. Then when I've put it into windows DVD maker, I get this problem.
Its strange because i've looked through all the setting but there doesn't seem to be any problem there?